In providing power to customers, electrical power utility companies employ a power grid distribution network that includes distribution-line-conductors (which are often referred to as power lines). Typically, difficulties or faults within the distribution network are identified only after occurrences of “events.” These events may merely result in a temporary loss of power for a limited number of customers, but more significant problems may occur.
Power utility companies typically employ line sensors to monitor faults on power lines. Such faults may be temporary or permanent (e.g., a blown fuse). In its usual application, the line sensor will appear passive during the normal operation of the power lines, and will activate when triggered by an overcurrent exceeding a programmed threshold.
A limited number of line sensors may include rechargeable cells harvesting solar energy and/or the electromagnetic field of the conductor to extend operational and communications availability. Harvesting energy from the electromagnetic field in the proximity of the conductor can be engineered with magnetic cores around the conductor, capturing the magnetic field created by line current flow and transforming it to an AC voltage. Split-core toroidal transformers can be mounted around a conductor, eliminating the need to cut and splice the conductors.
However, current line sensors suffer from two major shortcomings: the inability to measure phase voltage on the power line and the inability to operate continuously with zero line current.